In recent years, as an occupant protecting instrument for automobiles, the fitting of airbags has been rapidly spreading. The number of airbags fitted to automobiles has been increasing, examples of the airbags including an airbag for the driver seat and an airbag for the assistant driver's seat against frontal collision, airbags to protect femoral regions, fitted into seat sheets against lateral collision, and curtain airbags to be deployed along side windows. Furthermore, it is desired from the viewpoint of the downsizing of vehicles and an improvement in safety to deploy such an airbag at a high speed. Thus, the gas output of an inflator that generates gas to deploy the airbag is frequently set to a high level. However, an increase in the gas output with deployment of airbag at a high speed makes the inner pressure of the airbag high so that a large burden is given to sewn portions present in the airbag. For this reason, a request has been made that slippages between its fabric and its sewing threads should be reduced.
Thus, JP 2012-52280 A suggests an airbag fabric using yarns having a relatively low fineness of 200 to 320 dtex and high strength, and states that this makes it possible to give a fabric light in weight and high in strength. JP 2012-52280 A also states that use of the low fineness yarns makes an airbag small and light in weight and makes the outer surface of the airbag smooth so that the airbag can be deployed at a high speed.
JP 2007-196993 A suggests an airbag in which a resin containing a cobalt pigment is applied to a fabric to give excellent strength in a sewn portion and excellent edgecomb resistance.
However, the fabric disclosed specifically in JP 2012-52280 A is a fabric in which the density in the warp is larger than that in the weft. In that fabric, the balance between the elongation in the warp and that in the weft is poor so that when a high-temperature gas inflator is used, slippages are easily generated in the sewn portion of the airbag. Thus, that fabric is not sufficiently satisfied.
According to JP 2007-196993 A, the airbag is improved in strength of its sewn portion and in edgecomb resistance. However, when the fabric of that airbag is used in an airbag using a high-output inflator, the fabric is not yet sufficient in elongation, which has a large influence onto slippages in the sewn portion. Thus, it is difficult to apply that fabric, as it is, to such an airbag using a high-output inflator.
In light of such a background of conventional airbags, it could be helpful to provide an airbag fabric having excellent dimension stability and keeps its mechanical properties, and which is excellent in slippage amount and strength in the sewn portion against a burden onto the sewn portion of the airbag when the airbag is expanded and deployed; and an airbag comprising the airbag fabric.